1. Field
The invention is in the field of exercise machines, particularly stair stepping machines and machines which simulate movements made during snow skiing.
2. State of the Art
There are numerous stair stepping or climbing machines which provide foot treads on which a user stands and which then move vertically up and down to simulate a user climbing stairs. Various resistance means are used to adjust the resistance to movement of the treads to make the climb harder or easier, but all such machines provide only vertical tread movement with the treads generally moving in opposite vertical directions, i.e., one tread moving up while the other tread moves down. The vertical up and down movement, while simulating stair climbing and muscles used for stair climbing, does not exercise a variety of muscles and does not simulate skiing movements.
Conditioning is important for sports like alpine snow skiing since injuries are more likely to occur if a participant is not conditioned for the strenuous activity that occurs during skiing. Further, special muscles are used during skiing which are not necessarily exercised during conventional exercise programs or on many exercise machines such as stair steppers. Thus, a number of machines for simulating movements made during alpine snow skiing have been developed for use in training for skiing activities. Most of these machines include foot treads that move back and forth, some moving back and forth laterally in a plane with others moving back and forth in an arc. For example, U.S. Pat. No. 3,659,842 shows a pair of cantilever arms, each having a foot support and each pivotally secured to a base for lateral movement with respect to the pivot mounts. The arms are bent upwardly to provide a forwardly inclined position to the user and the pivots may be angled in parallel planes extending front to rear of the frame to angle the arms and foot supports as they pivot.
As another example, U.S. Pat. No. 4,846,463 shows a single arm pivotally secured to a base with a single platform mounted thereon to simultaneously support both feet of a user. The pivot axis of the arm is angled in a central plane from front to rear of the base so as the arm rotates or pivots, the platform travels in an arc with the low point of the arc at the center of its swing.
Most of the various exercise machines that attempt to simulate the action of skiing include foot treads that move similarly in angular and vertical displacement as they move from side to side. This however does not represent the movements encountered much of the time during skiing.